1. Field of the Invention
The present invention relates to an apparatus and a method for transmitting data in the MIDI protocol, and more particularly to a data sending apparatus and method and a data receiving apparatus and method in which contents data are converted to the MIDI format at the sending end and from the MIDI format at the receiving end for the data transmission in the MIDI protocol, and in which control commands for managing the data storing operation in the receiving end are further transmitted from the sending end in the MIDI protocol. The present invention also relates to a computer readable medium containing a computer program to configure and operate the above apparatuses and methods.
2. Description of the Prior Art
There have conventionally been known in the art various electronic musical apparatuses in a broad sense such as a keyboard apparatus which outputs musical performance data representing progression of tones according to manipulations of the keys and the controls in the keyboard apparatus, a tone generator apparatus which receives such musical performance data and generates and outputs musical tone signals according to the received performance data, a sequencer which automatically reads out stored musical performance data in a sequence with respect to time progression and generates and outputs tone signals according to the read-out musical performance data or outputs the read-out musical performance data per se, a data filer which receives such musical performance data and records and manages such data, and an electronic musical instrument including a keyboard and a tone generator, among which musical performance data are transmitted according to the MIDI protocol via MIDI interface circuits included in the respective electronic musical apparatuses. There have recently been introduced personal computers which incorporate MIDI interfaces, and generate, edit or record musical performance data therein and transmit such musical performance data to other electronic musical apparatuses using the MIDI format.
However, in the above-mentioned transmission of musical performance data according to the MIDI protocol, various control commands are not transmitted together with the performance contents data representing progression of tones, but only Ack/Nak messages are transmitted at the sending end and the receiving end to indicate that the data have been sent or not and that the data have been received or not, in which such Ack/Nak transmission is made per transmission of a prescribed small size (e.g. 256 bytes) of musical performance data. This causes a considerable amount of overhead and requires much time for transmitting musical performance data, which is disadvantageous for transmitting a large amount of musical performance data, especially in the case of transmitting waveform sample data. Further, in the case of transmitting the waveform sample data, the waveform sample data are transmitted as part of the musical performance data, and therefore the waveform sample data received in the receiving apparatus will be stored in a particular memory area within a tone generator or else which is unique to the receiving apparatus. Thus according to the conventional sending apparatus and receiving apparatus having a MIDI interface circuit, the storage area for the musical performance data cannot be arbitrarily designated in the receiving apparatus from the control of the sending end.